The present invention relates to a broadband service distribution method.
Modern telecommunications systems currently carry, in addition to ordinary voice calls, other services for users, including the transmission of television pictures and programming, such as cable television and data transmission services such as the well-known Internet.
The passband per user required to carry these services is far greater than the band required to carry ordinary telephony.
Accordingly, telecommunications companies are developing and installing so-called xe2x80x9cbroadband access networksxe2x80x9d.
These specialized networks are designed to carry digital signals to users, characterized by very wide passbands in the directions from the exchange to the user and with narrow bands in the opposite direction.
This is due to the fact that user requests occupy a small amount of band in comparison with the large amount of information downloaded to the user.
The broadband access network is usually constituted in a hybrid, i.e. mixed, manner by a fiber-optic part and by a coaxial-cable part and is accordingly termed xe2x80x9cHybrid Fiber Coaxial (HFC) networkxe2x80x9d.
Accordingly, FIG. 1 illustrates an exemplifying diagram in which the optical part is used to carry signals from one location, designated by the reference numeral 1 and termed xe2x80x9chead endxe2x80x9d, where the various programs to be fed into the broadband network are concentrated, to a point, designated by the reference numeral 2 and termed xe2x80x9cfiber nodexe2x80x9d, of the broadband network implemented with the hybrid fiber coaxial (HFC) network system, in which the optical signal that arrives from the fiber is converted into an electrical signal for transmission over coaxial cable.
The coaxial cables 4 used to distribute the signal to the users branch out from the fiber node 2, which is located proximate to the users, generally designated by the reference numeral 3.
Inside the building, and starting from the so-called xe2x80x9cnetwork terminationxe2x80x9d (NT), designated by the reference numeral 5, the coaxial cable 4 branches out, by means of a distribution system designated by the reference numeral 6, towards the individual users, designated by the reference numerals 7.
Special equipment is required, however, to receive the services: in the case of digital cable television, a special receiver is used which is capable of performing the following operations: tuning to a channel typically in the band between 47 and 862 MHz; decrypting the signal (in the case of pay channels); decompressing the signal according to the MPEG2 standard; and sending it to the television set, designated by the reference numeral 8, in the standard PAL format.
The above-described distribution system known as Hybrid Fiber Coaxial (HFC) network is used extensively because it is a solution having a good price/performance ratio.
This system, however, entails many drawbacks, including mainly the laying of coaxial cables inside buildings and along city streets.
Particularly in urban areas and in older buildings, laying said cables entails demolition and restoration work which is particularly expensive and sometimes altogether unacceptable for users.
In FIG. 1, the expression xe2x80x9cdistribution nodexe2x80x9d references the point of access to the broadband network for channels arriving from a plurality of head ends and at the same time the point of distribution of all the transmission channels towards the users.
As a partial solution to these drawbacks, which are worsened by the extent to which they force the user of the service to perform unwanted structural work, it is known, in order to transmit broadband signals efficiently and inexpensively, to use different systems, including the one known generically by the name xe2x80x9cbroadband asymmetric transmission systemxe2x80x9d or Asymmetric Digital Subscriber Loop (ADSL) or similar systems termed XDSL, where the letter X must be replaced in each case with the technology being used.
The expression ADSL designates a broadband transmission system capable of using the conventional telephone wire pair, designated by the reference numeral 9, to carry broadband digital channels simultaneously with the ordinary telephone service, also allowing communication between the user and the head end by means of a return channel (upstream channel) at low speed (differently from the downstream channel, which operates at high speed, hence he term xe2x80x9casymmetricxe2x80x9d).
The ADSL broadband asymmetric transmission system thus uses the ordinary wire pair, which currently reaches every home, to carry a broadband channel over said wire pair.
This ADSL broadband asymmetric transmission system preserves the ordinary service that can be used with a telephone set, designated by the reference numeral 10, and allows the user to request the chosen program or service from the service exchange by means of the upstream channel.
The exchange 50, however, must be capable of supplying the programs on demand and individually to each user: this type of service is known as Video On Demand (VOD) and entails the presence, in the exchange, of power and accordingly expensive equipment known as xe2x80x9cvideo serversxe2x80x9d, capable of serving the requests of users, or of equally expensive switching systems which typically use ATM (Asynchronous Transfer Mode) technology.
Substantially, the video server is a powerful computer capable of transmitting programs and services to users at the user""s request, while the ATM switch alternatively switches the requested channel towards the user.
Accordingly, any use of the ADSL broadband asymmetric transmission system configures the network as point-to-point, as shown schematically in the accompanying FIG. 2, between the exchange and the user, differently from the above-mentioned distribution structure known as hybrid fiber coaxial (HFC) network, in which the network gradually branches out from the exchange or head end to the users.
The ADSL broadband asymmetric transmission system therefore connects the user to broadband services only with a channel at a maximum rate of 8 Mbit/s and uses the existing wire pair, sharing it with the basic telephone services. This structure, however, entails very expensive equipment and a radical change in distribution concept.
The aim of the present invention is to solve the described technical problems, eliminating the drawbacks of the cited prior art and thus by providing a solution which allows to eliminate the costs and inconveniences of coaxial-cable wiring for the user.
Within the scope of this aim, an important object of the present invention is to provide a solution in which the end user does not have to perform any specific work at the masonry level in his home in order to utilize the broadband service.
Another important object of the present invention is to provide a solution which entails low implementation costs for the distribution of the broadband service.
Another important object of the present invention is to provide a solution which does not require the use of very expensive equipment such as powerful computers capable of serving the user""s requests.
This aim, these objects and others which will become apparent hereinafter, are achieved by a method for distributing broadband services characterized in that it provides for:
separating a broadband front end of a receiver from other portions of the circuit;
placing said front end in utility closets of a building;
connecting said front end to a so-called xe2x80x9cmodulator-demodulatorxe2x80x9d (ADSL modem) or to a so-called xe2x80x9cmodulatorxe2x80x9d or to an amplifier;
transferring a signal from said modulator-demodulator (ADSL modem) and from a telephone exchange to an adder or transferring the signal from said xe2x80x9cmodulatorxe2x80x9d or amplifier to an adder in order to mix the broadband and telephone services;
transferring the signals over a telephone wire pair to an individual end user; and
splitting the signals to a telephone and to a television set.